The objective of this study is the development of Raman and fluorescence methods for the study of biological membranes and model membrane systems. The ultimate goal is an understanding of the relationship of the physical properties of membrane bilayers and lipid-protein interactions to the biological functions of membranes. Unlabeled or deuterium labeled bilayers will be studied by conventional Raman spectroscopy with particular reference to recently developed molecular potential energy functions for hydrocarbon chains. The degree of depolarization of individual Raman lines will be studied near the phase transition region as a measure of the relative degree of melting of different sections of the phospholipid molecule. Bilayers and biological membranes will be labeled with conjugated linear polyenes. These probes will be studied by resonance Raman, ORD-CD, and fluorescence spectroscopy. The vibrational and fluorescence spectra, intensities and degree of polarization will be sensitive to the environment immediately surrounding the polyene. Energy transfer will probe longer distances. The degree of energy transfer from the aromatic amino acids of membrane bound proteins to the polyene will be determined. Fluctuations in this transfer due to polyene or protein motion will be measured. Biological membranes which naturally contain linear polyenes will also be studied by these methods and the effect of cis-trans isomerization on the physical properties of membranes will be investigated.